The present invention relates to a nail-shaped fastening element having a shank, at whose one end a tip is configured and at whose opposite other end a head is configured, and having a sleeve-shaped washer.
Fastening elements of this kind, such as nails made of steel, for example, are used in fastening technology, for example, to fasten components, such as formwork, for example, to hard materials, such as concrete, metal or stone. To this end, the fastening elements have a shank having a tip that is tapered in the setting direction and a head that is disposed at the other end of the shank and whose diameter is greater than that of the shank.
From U.S. Pat. No. 2,171,877, a fastening element in the form of a nail is known, which has a head and a shank that is contiguous thereto and that terminates in a tip. Fitted onto the shank is a washer which is in the form of a conical sleeve and whose largest cross section is disposed at its end facing the tip. A nail of this kind is suited, for example, for being driven into a workpiece by a hammer, the conical sleeve functioning as a spacer element which keeps the head spaced apart from the surface of the workpiece, once the nail is driven in, thereby allowing the nail to be pulled out of the workpiece again.
However, the disadvantage associated with this nail is that it is not suited for being driven in by a combustion-powered setting tool, for example, since the conical sleeve would also be driven into the workpiece or would be subject to spalling on the workpiece due to the high impact energy of such setting tools.
From U.S. Pat. No. 1,705,371, what is generally referred to as a double-headed nail is also known, which has two heads at its end facing opposite the tip. In this context, the lower head, which faces the tip and is formed as a circumferentially extending beading or collar, functions as a drive-in or penetration stop for the nail, while the second nail head, once it is driven into a workpiece, is spaced apart from the surface thereof, thereby allowing the nail to be pulled out of the workpiece again by a tool that is applied to the second head.
However, nails of this kind have the disadvantage of being characterized, on the one hand, by expensive manufacturing and, on the other hand, by poor variability in the use thereof.